Golf club with a striking face having improved characteristic time values

ABSTRACT

A ball striking face for a golf driver, fairway wood and hybrid type golf club head having a central impact area with a average thickness and additional multiple distinct areas outside the central impact area with other average face thicknesses for the improved transfer of energy to a golf ball for additional distance without any additional effort by the golfer. The striking face provides a transfer of energy at the central impact area which does not exceed CT values of 257 u sec. and an improved transfer of energy in one or more areas outside the central impact area that provides CT values greater than 257 u sec. but not greater than 275 u sec. when tested with the United States Golf Association&#39;s CT test protocol.

BACKGROUND OF THE INVENTION

The present invention relates to golf clubs and in particular todrivers, fairway woods and hybrids having an improved club head,striking face configuration.

The Characteristic Time, hereinafter CT, has been commonly known asmeasuring the “spring-like” or “trampoline” effect of a driver, fairwaywood or hybrid face or more formally as a measurement of the Coefficientof Restitution of those faces. The CT is recognized in terms of microseconds and will be referred to hereinafter as u sec.

A wide variety of club head configurations, weighting structures, andstriking face features have been proposed and presented to the golfingmarketplace to achieve increased performance with these clubs.

However, the focus on increasing the spring-like or trampoline effectfor the club face has been in terms of making the center or near centerof the face having the highest CT. This is because tour professionalshit the center or very near center of the face. Another reason the CT isthe highest in the center of the face is a byproduct of historicalmanufacturing construction.

Although most drivers have titanium faces, most other conventional metalwood type golf clubs and hybrid golf clubs are made with steel facesbecause of lower material and manufacturing costs. The clubs with steelfaces provide little spring-like or trampoline effect as compared tosimilar clubs with titanium faces. In addition, various attempts havebeen made, as represented in prior art patents, to improve the strikingface configuration of golf clubs for better performance.

U.S. Pat. Nos. 6,659,884, 6,659,885, 7,131,912, 7,273,421 and 7,481,717to Knuth are directed to golf club heads having an improved faceconfiguration using different thicknesses and parabolic shaped sectionsto improve performance across the face.

U.S. Pat. Nos. 5,830,084, and 6,368,234 assigned to Callaway and U.S.Pat. No. 5,954,596 assigned to Ping, among others, are directed to metalwood golf clubs having a striking face with various thicknesses.

The United States Golf Association, USGA, is the governing body of golfin the United States and publishes the Rules of Golf that includesequipment standards in order that golf clubs are deemed conforming.Non-conforming clubs may not be used in all professional and mostnon-professional tournaments or for golfers to obtain and maintain aUSGA handicap index.

One of the USGA rules relating to equipment limits the transfer ofenergy to a golf ball due to the spring-like or trampoline effect of thestriking face of a golf club. This rule seeks a limit on this effect torestrict the distance that golf clubs are able to hit a golf ball inorder to preserve the challenges of existing golf courses. The limit isembodied in their former Coefficient of Restitution, COR, rule which isa measurement of the energy transfer in a collision of two objects. TheUSGA established a COR limit of 0.830 on driver, fairway wood and hybridgolf club faces, which means that if more than 83% of the energy istransferred in the collision of the driver head with a golf ball, theclub head would be deemed non-conforming with the USGA rules.

In the early 2000s the USGA established the Characteristic Time, CT,test to determine whether a golf club head conformed to or exceeded theCOR limitation. The CT test includes positioning the head so a pendulumarm with a sensor strikes the face at a variety of locations at thecenter and off-center. The speed of the pendulum as it bounces off theface determines the CT value. It was determined a CT measurement of 257microseconds, 257 u sec, corresponds to a COR of 0.830 and thisestablished the CT limit for anywhere on the face. Any driver, fairwaywood or hybrid golf that had a CT measurement in excess of 257 u secanywhere on the face was non-conforming under the USGA rules.

Recently the USGA amended the CT rule to identify an area it called theImpact Area as having a width of 42.67 mm or 1.68 inches in the centerof the face of a driver, fairway wood and hybrid and a height from thecrown down to the sole with the exception of 6.35 mm within the sole andcrown excluded. Refer to FIG. 1 of the drawings to view an example ofthe Impact Area of a driver face. The remaining face area to the rightand left of the Impact Area is defined herein as the “Outside the ImpactArea.” The USGA CT rule further states the prior CT limit of 257 u secapplies only inside the Impact Area and permits the CT to be up to 275 usec in the Outside the Impact Area.

SUMMARY OF THE INVENTION

The present invention relates to a driver, fairway wood and hybrid clubhaving an improved striking face design used with these clubs in animproved club face characteristic time, CT. These clubs are the first touse a face that is 257 u sec or less in the entire Impact Area but hasareas that are greater than 257 u sec in the Outside Impact Area but arenot over 275 u sec anywhere in that area.

The club heads of the present invention are formed with a titanium or atitanium alloy striking face that produces a higher CT than conventionalsteel face clubs in the Impact Area up to 257 u sec. The club face ofthe present invention also produces a CT in the Outside the Impact Areathat exceeds 257 u sec and the absence of any CT over 275 u sec. The CTvalues of the present invention are accomplished as a result ofdifferent zones of variable thickness in the faces as identified below.

It will be appreciated that there are different zones of height, widthand thickness for the driver, fairway woods and hybrids. The reason isthe preferable widths, heights and thicknesses of each of these clubsare different and those differences can affect the spring-like ortrampoline effect of those faces because a larger face, by virtue of itsgreater size will have a higher CT for the same thickness in therelatively same location.

It will be further appreciated that the same object of the inventioncould be achieved if areas identified below in the Impact Area or theOutside the Impact Area have one uniform thickness or multiplethicknesses and one or more different shapes of uniform or variablethicknesses, including the absence of a rectangular shape. The averagethicknesses of the areas described below have been found to achieve theobject of the present invention even if one or more different shapes areused that overlap part or all of the areas described below. As a result,a golf ball struck with the club achieves less loss of energy off theclub face when the ball is struck on areas both within the Impact Areaand Outside the Impact Area but within the USGA allowable limit.

The benefit of this design creates CT values between 250 and 257 u secin the center and other areas in the Impact Area and CT values between257 and 275 u sec in the Outside the Impact Area where there istypically a larger loss of energy as a result of an off-center, miss-hitof the golf ball against the striking face of the club head that resultsin loss of both distance and accuracy.

It will be appreciated the improved striking faces of the presentinvention may be used with drivers having a variety of different loftsthat are typically within a range of 8 to 13 degrees, fairway woodshaving lofts that are typically within a range of 13 to 21 degrees andmetal hybrid golf clubs that have lofts typically between 15 and 26degrees.

Among the objects of the present invention is the provision of a metalgolf club that has areas of CT values at or near the USGA limits in theImpact Area and CT values higher than 257 u sec and approaching 275 usec in the Outside Impact Area.

This and other objects will be appreciated with reference to thefollowing specification and accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a frontal view of the striking face of a golf driver inaccordance with the present invention.

FIG. 2 is a frontal view of the striking face of a fairway wood inaccordance with the present invention.

FIG. 3 is a frontal view of the striking face of a hybrid in accordancewith the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, the drawings illustrate a driver golf club head 100in accordance with the present invention. The club head 100 includes ahose 102 for connection to a conventional shaft and upper grip (notshown). The club head 100 includes a frontal ball striking face 104 madewith and/or secured to a club head body 106 having an upper crown 108,bottom sole 109 and sides 110.

The striking face 104 preferably in the present embodiment is wide andextends between the toe 112 and heel 113 of the club head 100 with CTvalues up to the USGA's 257 u sec limit in the Impact Area 115 andgreater than 257 u sec and approaching the 275 u sec limit in theOutside Impact Areas 116 and 117.

FIG. 1 shows a driver golf club with a frontal ball striking face 104.The driver has an area that is located an equal distance from the crownand the sole and is 4.267 cm wide and 2.4 cm in height in the ImpactArea 115 with an average thickness between 2.8 and 3.4 mm. The combinedthickness of the areas above and below the central part of the ImpactArea 115 can have the same, thicker or thinner average thickness.Preferably, these areas will have an average thickness less than 2.8 mmto increase the CT in those areas. The areas immediately to the rightand left of the Impact Area in the Outside Impact Area 116 and 117 areequal distance from the crown and the sole and are 2.4 cm high and 1.3cm wide. These areas have an average thickness between 2.2 and 2.6 mm.The remaining heel and toe areas in can have the same, thicker orthinner average dimension. Preferably, these areas will have an averagethickness less than 2.2 mm to increase the CT in those areas.

FIG. 2 shows a fairway wood type golf club with a frontal ball strikingface 204. The central part of the fairway wood 215 has an area locatedan equal distance from the crown and the sole in the Impact Area and is2.0 cm high and 4.267 cm wide 215 with an average thickness between 2.1and 2.5 mm. The combined thickness of the areas above and below thiscentral area can have the same, thicker or thinner average thickness,preferably an average thickness of 2.1 mm or less to increase the CT inthose areas. The areas immediately right and left of the Impact Area 216and 217 are located an equal distance between the crown and the sole andare 2.0 cm high and 0.7 cm wide with an average thickness between 1.3 mmand 1.9 mm. The remaining heel and toe areas can have the same, thickeror thinner average thickness dimension. Preferably these areas will havean average thickness less than 1.3 mm to increase the CT in those areas.

FIG. 3 shows a hybrid type golf club with a frontal ball striking face304. The central part of the Impact Area 315 is 2.0 cm high and 4.267 cmwide. The hybrid type golf club has an area located an equal distancefrom the crown and the sole in the Impact Area and is 2.0 cm high, 4.267cm wide 315 and has an average thickness between 2.2 and 2.6 mm. Thecombined thickness of the areas above and below this central area canhave the same, thicker or thinner average thickness, but preferably anaverage thickness of 2.2 mm or less to increase the CT in those areas.The areas immediately right and left of the Impact Area in the Outsidethe Impact Area 315 and 316 are located an equal distance from the crownand sole; and are 2.0 cm high and 0.7 cm wide. These areas have anaverage thickness between 1.6 mm and 2.0 mm. The remaining heel and toeareas can have the same, thicker or thinner average thickness dimension.Preferably these areas will have an average thickness less than 1.6 mmto increase the CT in those areas.

It will be appreciated that the above example of a preferred embodimentand the thicknesses disclosed are not limiting but may be altered inkeeping within the concept of the invention.

1-23. (canceled)
 24. A ball striking face characterized for use with adriver type metal wood golf head having a ball striking face, an uppercrown, heel, toe, and a bottom sole; said striking face having a centralimpact area with an average thickness between approximately 2.8 mm andapproximately 3.4 mm; said striking face being further defined by anadditional area located adjacent to the toe side of said impact area andan additional area located adjacent to the heel side of said centralimpact area; said additional adjacent areas on either side of saidcentral impact area having an average thickness between approximately2.2 mm and approximately 2.6 mm; said striking face having remainingareas outside said central impact area and outside said additional areasadjacent to and on either side of said central impact area; and, saidstriking face being further defined by said central impact area having acharacteristic time, CT, value no greater than 257 u sec. and by one ormore of the areas outside said central impact area having CT valuesgreater than 257 u sec. but not greater than 275 u sec.
 25. The ballstriking face of claim 24 wherein said central impact area isapproximately 4.3 cm wide and approximately 2.4 cm high and saidadditional adjacent areas on either side of said central impact area areapproximately 1.3 cm wide and approximately 2.4 cm high.
 26. Thestriking face of claim 25 wherein said central impact area and saidadditional adjacent areas on either side of said central impact area arerectangular.
 27. The striking face of claim 24 wherein said centralimpact area is located on said face at an equal distance from said uppercrown and said bottom sole.
 28. The striking face of claim 24 whereinsaid two additional adjacent areas located on either side of saidcentral impact are located at an equal distance from said upper crownand said bottom sole.
 29. The striking face of claim 24 being furtherdefined by remaining areas between said central impact area and saidupper crown and between said impact area and said bottom sole having anaverage thickness that is the same, thicker, or thinner than the averagethickness of said central impact area.
 30. The striking face of claim 24being further defined by said all remaining areas to said heel side andto said toe side of said central impact area and said additionaladjacent areas located on either side of said central impact area; saidremaining areas each having an average thickness the same, thicker, orthinner thickness than the average thickness of said two additionaladjacent areas on either side of the central impact area.
 31. A ballstriking face characterized for use with a fairway type metal wood golfhead having a ball striking face, an upper crown, heel, toe, and abottom sole; said striking face having a central impact area with anaverage thickness between approximately 2.1 mm and approximately 2.5 mm,said striking face being further defined by an additional area locatedadjacent to the toe side of said impact area and an additional arealocated adjacent to the heel side of said central impact area; saidadditional adjacent areas on either side of said central impact areahaving an average thickness between approximately 1.3 mm andapproximately 1.9 mm; said striking face having remaining areas outsidesaid central impact area and outside said additional areas adjacent toand on either side of said central impact area; and, said striking facebeing further defined by said central impact area having acharacteristic time, CT, value no greater than 257 u sec. and by one ormore of the areas outside said central impact area having CT valuesgreater than 257 u sec. but not greater than 275 u sec.
 32. The ballstriking face of claim 31 wherein said central impact area isapproximately 4.3 cm wide and approximately 2.0 cm high and saidadditional adjacent areas on either side of said central impact area areapproximately 0.7 cm wide and approximately 2.0 cm high.
 33. Thestriking face of claim 32 wherein said central impact area and saidadditional adjacent areas on either side of said central impact area arerectangular.
 34. The striking face of claim 31 wherein said centralimpact area is located on said face at an equal distance from said uppercrown and said bottom sole.
 35. The striking face of claim 31 whereinsaid two additional adjacent areas located on either side of saidcentral impact are located at an equal distance from said upper crownand said bottom sole.
 36. The striking face of claim 31 being furtherdefined by remaining areas between said central impact area and saidupper crown and between said impact area and said bottom sole having anaverage thickness that is the same, thicker, or thinner than the averagethickness of said central impact area.
 37. The striking face of claim 31being further defined by said all remaining areas to said heel side andto said toe side of said central impact area and said additionaladjacent areas located on either side of said central impact area; saidremaining areas each having an average thickness the same, thicker, orthinner thickness than the average thickness of said two additionaladjacent areas on either side of the central impact area.
 38. A ballstriking face characterized for use with a hybrid type metal wood golfhead having a ball striking face, an upper crown, heel, toe, and abottom sole; said striking face having a central impact area with anaverage thickness between approximately 2.2 mm and approximately 2.6 mm;said striking face being further defined by an additional area locatedadjacent to the toe side of said impact area and an additional arealocated adjacent to the heel side of said central impact area; saidadditional adjacent areas on either side of said central impact areahaving an average thickness between approximately 1.6 mm andapproximately 2.0 mm; said striking face having remaining areas outsidesaid central impact area and said additional areas adjacent to and oneither side of said central impact area; and, said striking face beingfurther defined by said central impact area having a characteristictime, CT, value no greater than 257 u sec. and by one or more of theareas outside said central impact area having CT values greater than 257u sec. but not greater than 275 u sec.
 39. The ball striking face ofclaim 38 wherein said central impact area is approximately 4.3 cm wideand approximately 2.0 cm high and said additional adjacent areas oneither side of said central impact area are approximately 0.7 cm wideand approximately 1.6 cm high.
 40. The striking face of claim 39 whereinsaid central impact area and said additional adjacent areas on eitherside of said central impact area are rectangular.
 41. The striking faceof claim 38 wherein said central impact area is located on said face atan equal distance from said upper crown and said bottom sole.
 42. Thestriking face of claim 38 wherein said two additional adjacent areaslocated on either side of said central impact are located at an equaldistance from said upper crown and said bottom sole.
 43. The strikingface of claim 38 being further defined by remaining areas between saidcentral impact area and said upper crown and between said impact areaand said bottom sole having an average thickness that is the same,thicker, or thinner than the average thickness between approximately 2.1and approximately 2.5 mm.
 44. The striking face of claim 38 beingfurther defined by said all remaining areas to said heel side and tosaid toe side of said central impact area and said additional adjacentareas located on either side of said central impact area; said remainingareas each having an average thickness the same, thicker, or thinnerthickness than the average thickness of said two additional adjacentareas on either side of the central impact area.